Within the field of cutting tools used in drilling and boring operations, there are many examples of cutting inserts being removably secured in a tool shank. In some instances, these cutting tools are configured such that the cutting insert is removably secured in the tool shank by means of a clamping bolt.
U.S. Pat. No. 6,514,019 discloses a boring tool comprising a holder, a cutting insert and a clamping bolt for fastening the cutting insert to a head portion of the holder. The head portion includes a groove bounded by two groove side faces formed on two groove branches. During assembly of the boring tool, the cutting insert is located in the groove, and two insert side faces on the cutting insert are clamped between the two groove side faces by the clamping bolt. The clamping bolt passes through a bore portion in a first groove branch, and also through a receiving bore in the cutting insert, before engaging an internal thread in a second groove branch. The receiving bore only opens out to the two insert side faces, and thus the cutting insert can only be removed from the holder following disengagement of the clamping bolt from the internal thread and withdrawal of the clamping bolt from the receiving bore.
U.S. Pat. No. 7,168,893 discloses a throw-away drill comprising a drill main body, a tip and a clamping bolt for fastening the tip to a tip attachment seat cut into an end portion of the drill main body. The end portion is divided into first and second end portions having a pair of internal side surfaces. During assembly of the throw-way drill, the tip is located between the first and second end portions, and a pair of outer side surfaces on the tip is clamped between the pair of internal side surfaces by the clamping bolt. The clamping bolt passes through a through hole in the first end portion, and also through a cutaway portion in the tip, before engaging a threaded portion in the second end portion.
The cutaway portion opens out to the pair of outer side surfaces and also to a rear edge face adjacent the pair of outer side surfaces, allowing the throw-way drill to be unclamped and the tip to be removed from the drill main body without disengagement of the clamping bolt from the threaded portion. The cutaway portion includes no safety feature to prevent the tip from being inadvertently ‘pulled’ from the drill main body.